Nuclear magnetic resonance (NMR) has seen increasing acceptance in recent years as a diagnostic tool for producing images of the interior portions of the human body. NMR diagnostic medical imaging is particularly attractive since it does not subject a patient to the potentially hazardous x-rays utilized in most prior art imaging technology. However, a disadvantage of NMR diagnostic use is the relatively long scan time required in order to form certain images. Presently, the scan time can be on the order of about five minutes or more for many human imaging applications, and this lengthy scan time serves to limit the clinical usefulness of NMR imaging in certain applications.
One of the major impediments to high speed magnetic resonance imaging is the long time required for data acquisition and reconstruction. To date no method is known which can image in "realtime". That is to say, a method has not as yet been devised in which NMR signals are acquired and used to immediately generate a reconstruction and provide an image within about 100 milliseconds or less.
The deficiency of the prior art is the belief that all spectral components of an image must be acquired before the image can be reconstructed. The novelty of the present invention is the recognition that immediately after each spectral component or signal is acquired, it is used to update the NMR image being displayed on a video monitor or the like within about 50-100 milliseconds. Moreover, the method and apparatus of the present invention provide for instantaneous interactive operator control of image parameters so as to allow, for example, for selective adjustment of the angulation or obliqueness of an image slice.